It is known that reducing the temperature of a part of the human or animal body by the application of Cryotherapy following injury and/or surgery reduces swelling and pain and expedites healing. Likewise, the maintenance of a constant temperature during surgery is extremely important to reduce internal bleeding, bruising and swelling. Cryotherapy is also known to be beneficial as part of a sports training program when applied before and after sporting events and periods of intense physical activity.
Studies have shown that the optimum benefit to be gained by cooling and maintaining the body temperature is achieved by reducing the temperature in the affected area as soon as possible after the injury has occurred or surgery has commenced. Studies have also shown that simply applying excessively low temperatures to the target area does not achieve the optimum cooling effect and can be harmful to the patient as it can cause the onset of cold burn or frostbite.
Known methods for effecting localized temperature reduction of various parts of the human body require the use of cumbersome cooling pads, ice packs, frozen gels and the like. A problem of such methods of quickly reducing the body temperature is that the rate at which they reduce the body temperature is slow. A further problem is that due to this slow rate of body temperature reduction, there is a tendency for excessively low temperatures to be applied to the injury site in an attempt to achieve a more rapid rate of temperature reduction and make the treatment more effective. A further problem is that when ice packs and the like are placed on an injury site, the ice begins to melt and provide a constantly changing and uncontrollable temperature.
It is known that the principle cause of the delay and ineffectiveness of the heat transfer is due to the extremely small ‘real’ area of contact at the microscopic level between the applicator and the treatment site. Studies have shown that the ‘real’ area of contact is less than around 5% of the total area over which optimum heat transfer could occur, the remainder of the area being made up of air gaps. The concentration of the flow of heat at the points of contact creates ‘hot spots’ which increase the localized temperature and melt the surrounding ice or gel pack.
The applicant has appreciated that the full potential benefits of Cryotherapy are not being exploited by the known apparatuses for the fast application of cooling.
The applicant has also appreciated that to improve the efficiency of heat transfer between an applicator and the treatment site, there is a need for an improved interface between the applicator and treatment site that closely conforms to the contours of the area of a patient's body undergoing treatment in order to maximize the real contact area between the applicator and treatment site. The inventor has also previously appreciated that the thermal conductivity of the interface must be high and barriers to heat transfer minimized in order to optimize the efficiency of heat transfer and thereby permit the maximum cooling effect to be applied in the shortest space of time.
United Kingdom patent application no. GB0416879.5 describes a device addressing these concerns.